Warren Gatland has raised the prospect of a quota system being introduced to the British & Irish Lions for their next tour, a 2017 trip to New Zealand to tangle with the All Blacks.

Gatland last week agreed to extend his contract with Wales through to the 2019 World Cup.

That means the Kiwi's name will top the list of potential Lions coaches after his success in Australia this year where the combined side beat the Wallabies 2-1 in the test series.

But Gatland said the selection problems he encountered this year, especially with the controversial axing of Irish and Lions legend Brian O'Driscoll for the series decider, had opened a can of worms.

Do the Lions need to introduce some sort of selection guidelines to ensure proper representation across the four contributing nations - England, Ireland, Wales and Scotland?

The squad that toured Australia was dominated by Wales, who had 10 players appearing in the final test. The 2009 tour to South Africa was dominated by Ireland players and the 1993 trip to New Zealand by England. The representation tends to reflect the relative strengths of the individual nations at the time. Not one Scot started any of this year's internationals.

Despite winning the series, Gatland came in for criticism for his supposed pro-Welsh and anti-Irish bias. That came to a head in the final week of the tour with the furore over the dropping of O'Driscoll.

"What happened in the last week and the non-selection of Brian, that brought that issue to the fore," Gatland said as he tabled his report on the Australian tour to the Lions committee.

"That personal stuff got to me. The debate needs to be in the public domain. It is not my decision.

"Do we want or need a minimum number of players from a country in the squad and then, when we are picking a test side, does there need to be a minimum from each country in the starting XV?

"I think I know what the answer will be with that, but, if we don't raise it and debate it to get a consensus, then potentially we are going to end up with what we had recently on this tour."

Gatland said that the tour of Australia, with its relentless schedule of two games a week, was the most mentally challenging of his life.

His report to the Lions committee also suggested that pressure should be brought to bear on the southern hemisphere nations to make a Lions tour the priority by fielding full-strength teams in the warmup games and midweek matches.

"We need to negotiate with them because the Lions tour means so much to everyone," Gatland said. "It generates so much money."

Gatland said he had no hesitation in extending his Welsh contract because he felt there was so much potential. He now has two more World Cups to prove that.

He said he didn't consider the All Blacks coaching job in making his decision.

"There was no thought in my process about coaching the All Blacks. I don't think about planning what I want to do - I'm a great believer in what will be, will be," Gatland said, believing time was on his side for a possible return to New Zealand.

"I'm only 50 so still a really young coach, so plenty of time to look at other opportunities in the future."